<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Caitou-Xiaomi</title>
  <style>
    .bigblock {
      width: 622px;
      height: 312px;
      background-color: #ffffff;
      border: 1px solid #E9E9E9
    }
    .bigblock div {
      border: 1px solid #E9E9E9
    }
    .B1 {
      background-image: url(B1.jpg);
      width: 309px;
      height: 309px;
      float: left;
    }
    .B2 {
      background-image: url(B2.jpg);
      width: 309px;
      height: 154px;
      float: right
    }
    .B3 {
      background-image: url(B3.jpg);
      width: 309px;
      height: 154px;
      float: right
    }
  </style>
</head>

<body>
  <div class="bigblock">
    <div class="B1"></div>
    <div class="B2"></div>
    <div class="B3"></div>
  </div>
  
</body>
</html>